Roller bit



July 25, 1933. T. H STANCUFF 1,920,164-

Patented July 25, .1933

UNITED-STATES PATENT OFFICE THOMAS H. STANCLIFF, 0F HOUSTON, TEXAS, ASSIGNOR ATO REED ROLLER BIT COMPANY, OF HOUSTON, TEXAS, A CORPORATION OF TEXAS ROLLER BIT Reled for abandoned application Serial No. 604,446, filed April 11, 1932. This application filed January This invention relates generally to deep well drilling apparatus and specifically to roller bits, this application being substituted for my application Serial Number 604,446,

' filed April 11, 1932.

It has for its object the provision of a new and improved roller bit embodying only a few large cutters arranged to cut hard and soft formations.

The preferred embodiment of the invention is illustrated by the accompanying drawing, of which Fig. 1 is a fragmentary sectional elevation of the bit; and Fig. 2 a bottom plan view thereof.

lin the drawing, the bit head is indicated at 1. It is attached to the conventional drill stem not shown. On the lower end of the bit head 1 are three depending bearing projections 2, 3 and 4. The projection 2 has a downwardly opening cutter pin slot 5 and an inner wall 6 substantially parallel with the longitudinal axis of the head. rlhe pron jection 3 has a ldownwardly opening slot 7 and an inner wall 8 inclined upwardly and inwardly toward the longitudinalaxis of the head. rlhe projection 4 has a downwardly opening slot 9 and an inner wall 10 substantially parallel with the longitudinal axis of the head.

The numeral 11 indicates a cutter support having a cutter pin 12 slidable upwardly in the slot 5 of projection 2 and disposed at substantially a right angle to the longitudinal axis of the head; a cutter pin 13 slidable upwardly in slot 7 of projection 3 and disposed at substantially a right angle to the inner wall 8 of projection 3; and a pin 14 slidable upwardly in slot 9 of projection 4 and disposed at substantially a right angle to pins 12 and 13 and offset from the longitudinal axis of the head.

On the pin 12 is a first roller cutter 15;`

on the pin 13 is a second roller cutter 16;

and on the pin 14 is a third roller cutter 17. The first roller cutter 15 is disposed adjacent the periphery of the head. The second roller cutter 16 projects from the periphery of the head and cuts a path outsideethe path cut by the rst cutter 15. The third cutter 17 is disposed adjacent the longitudinal axis Serial N0. 653,348.

of the head and cuts a path inside the path cut by the first cutter 15.

The head 1 may be provided with passagel v2l, 22Kand 23 to support the cutters 15, 16

and 17, respectively; and washers 24, 25 and 26 may be placed on the outer sides of said cutters, as shown. The numeral 27 indicates roller bearings that may be employed if desired.

The support 11 with the cutters 15, 16 and 17 on the pins 12, 13 and 14 may be inserted in and removed from the head as a unit. To hold the parts in place, the pins 12, 13 and 14 may be welded in the slots 5, 7 and 9, respectively..

In deep well drilling, both hard and soft formations are frequently encountered, disposed within a few feet of each other. Conventional rock bits are construct-ed to cut only hard formations, and conventional soft formation bits are constructed to cut only soft formations. And so when a rock bit on the drill stem cuts through a hard formation Vand enters a soft formation, the drill stem must be removed and a soft formation bit substituted for the rock bit. And when a hard formation is again encountered, the drill stem must be again removed and a rock bit substituted for the soft formation bit.

The bit provided by this invention embodies only a few large cutters arranged to cut both hard and soft formations. The many advantages of this bit will be apparent to those skilled in the art.

I claim:

1. A roller bit head having a pair of oppositely disposed depending projections, the inner wall of the first of said projections being substantially parallel with the longitudinal axis of the head, and the inner wall of the second of said projections being inclined upwardly and inwardly toward the longitudinal axis of the head, said projections having therein downwardly opening cutter pin slots; said head having' a third depending proection at substantially a right angle to the first of said pair of projectlons, said third projection having therein a downwardly opening cutter pin slot and being offset from the longitudinal axis of the head; and a cutter support having three cutter pins slidable into said slots in said projections, the pins slidable into the slots of said first and third projections being disposed at subtantially a right angle to the longitudinal axis of said head, and the pin slidable into the slot of said second projection being disposed at substantially a right angle to the inner wall of said second projection; and a roller cutter on each of said pins; the lowermost cutting edge of the roller cutter adjacent said second projection being above the lowermost cuttingedges of the roller cutters adjacent said first and third projections; said cutters being arranged to cut an area greater than the transverse area of said head.

2. A roller bit head having a pair of oppositely disposed depending projections, the inner wall of the first of said projections being substantially parallel with the 'I longitudinal axis of the head, and the inner wall of the second of said projections being inclined upwardly and inwardly toward the longitudinal axis of the head, said projections having therein downwardly opening 'i cutter pin slots; said head having a third depending projection at substantially a right angle to the first of said pair of projections, said third projection having therein a downwardly opening cutter pin slot ;v

a cutter support having three cutter pins slidable into said slots in said projections, the pins slidable into the slots of said first and third projections being disposed at substantially a right angle to the longitudinal 497 axis of said head, and the pin slidable into the slot of saidjs'econd projection being disposed at substantially a right angle'to the inni-`- W'all of said second projection; and

a roller cutter on each of said pins; said cutters being arranged to cut an area greater than the transverse area of said head.

3. A roller bit having a head, and three roller cuttersmounted in said head; the first of said cutters being mounted adjacent the' said head on an axis at substantially a right angle to the axis of said first cutter to cut a. path inside the path cut by said first cutter, said third cutter being offset from the longitudinal axis of' said head.

4. A roller bit having a head, and three roller cutters mounted in said head; the first of' said cutters being mounted adjacent the peripherly of said head on an axis at substantially a right angle to the longitudinal axis of said head; the second of said cutters being mount-ed opposite said first cutter to project beyond the periphery of said head on an axis inclined upwardly and outwardly from the longitudinal axis of said head, to

cut a path outside of the path cut by said first cutter; the third of said cutters being mounted adjacent the longitudinal axis of said head on an axis at substantially a right angle to the axis of said first cutter to cut i" a. path inside the path cut by said first cutter.

5. A roller bit having a head, and three roller cutters mounted in said head, one of said cutters projecting beyond the periphery ol said head on an axis inclined upwardly and outwardly from the longitudinal axis of said head,the other cutters being mounted on axes at an angle to each other and at substantially a right angle to the longitudinal axis of said head to cut the formation substantially from the longitudinal axis of said head to the path cut by said first mentioned cutter.

6. A roller bit having a head and three substantially cylindrical roller cutters mounted in said head to cut an area greater than the transverse area of said head, one of said cuttersbeingmounted on an axis inclined upwardly and outwardly from the longitudinal axis of said head, and projecting beyond the periphery of'said head, the other cutters being mounted on axes at substantially a right angle to each other and at substantially a right angle to the longitudinal axis of the head.

7. A bit head having oppositely disposed peripheral depending projections, the inner wall of one of said projections being inclined upwardly and linwardly toward the longitudinal axis of said head, and the inner wall of the other of said projections heilig substantially parallel with the longitudinal axis oi said head; and a third depending'v projection between said pair of projections and Within the periphery of said head, the inner Wall ofl said third projection being substantially parallel with the longitudinal axis of said head.

THOMAS H. STANCLIFF.

'all 

